On the oxidation of kraft pulp - Formation of carbonyl groups during acidic hydrogen peroxide oxidation
Licentiate thesis, 2020
Oxidative chemistry is typically utilized in the production of bleached qualities of chemical pulp. These processes are optimized to minimize effects on the carbohydrate structures, as this would lead to yield loss or undesirable effects, such as yellowing of the pulp. Altering the conditions in a bleaching stage to favour the introduction of carbonyl groups would allow a carbonyl-rich pulp, with inherent wet-strength, to be produced on a large scale using the existing infrastructure of pulp mills.
The main aim of this work has been to evaluate the oxidation of bleached softwood and hardwood kraft pulp using a common bleaching agent: hydrogen peroxide. Process conditions, such as pH and temperature, have been varied and their influence on the formation of oxidized functionalities and the degradation of the carbohydrates has been analysed. It was found that a pH of 4 greatly increased the formation of carbonyl groups, compared to the traditional alkaline conditions of a hydrogen peroxide stage. Sheets produced from the oxidized pulp showed a significantly enhanced durability at aqueous conditions and were also found to withstand mild stirring in water while exhibiting only limited swelling.
Chalmers, Chemistry and Chemical Engineering, Chemical Technology, Forest Products and Chemical Engineering
Modification of softwood kraft pulp fibres using hydrogen peroxide at acidic conditions
Cellulose,; Vol. 27(2020)p. 7191-7202
Martinsson A, Hasani M, Theliander H. Hardwood kraft pulp fibre oxidation using acidic hydrogen peroxide
AvanCell - Creating novel pulp fibre
Södra, 2017-01-01 -- 2020-12-31.
Paper, Pulp and Fiber Technology
Chalmers University of Technology
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